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A porous polyether ether ketone (p-PEEK) was fabricated by firstly preparing titanium/PEEK composite (Ti/PEEK) (die casting) and then removing titanium wire (acid etching). The pores in p-PEEK can provide channels for bone cells ingrowth and body fluid transmission. The pore size and porosity of p-PEEK can be tailored by adjusting the diameter and volume fraction of titanium wire that was used in the preparation process. The average cell wall thicknesses of p-PEEK with porosities of 30 ± 1.5%, 40 ± 2.0% and 50 ± 2.5% were 326.4 μm, 297.6 μm and 255.4 μm, respectively. The compressive yield strengths and the elastic moduli of p-PEEK with porosities ranged of 30%–50% were 28–16 MPa and 5.5–3.0 GPa, respectively. The elastic modulus of p-PEEK reached the floor level of cortical bone (3.0–30.0 GPa). The relationship of the relative elastic moduli to the relative densities of p-PEEK conformed to the Gibson-Ashby model. This porous PEEK is expected to be a candidate for hard tissue implant materials. [ABSTRACT FROM AUTHOR]

A new approach to fabrication of porous titanium by using the molybdenum wire as space holder was developed, in which titanium liquid was cast into the entangled molybdenum wires in a vacuum environment, and followed by etching off the space holder material in an aqua regia solution. This infiltration casting and acid corrosion method fabricated the porous titanium with different porosities with a pore diameter of 0.4 mm. The porous titanium with the porosity of 32–47% exhibited the Young's modulus in the range of 23–62 GPa and the yielding strength in the range of 76–192 MPa. The adhesion and spreadability of the bovine osteoblast cells on the porous titanium were also evaluated in vitro. The porous titanium with 47% porosity has great potential for implant applications. [ABSTRACT FROM AUTHOR]

Our aim was to develop a biocompatible bone repair material that has the advantage of preventing postoperative infections. Finally, the porous magnesium (p-Mg) loaded with gentamicin sulphate (GS-loaded Mg-G) was fabricated. The GS release behavior of the GS-loaded Mg-G in phosphate buffer saline (PBS) was investigated. The effective release time of GS reached to 14 days. In addition, the effects of porosity and pore diameter of p-Mg on the GS release behavior of the GS-loaded Mg-G were studied. In the initial burst release stage, the GS release rate of the GS-loaded Mg-G increased with the increasing porosity or the increasing pore diameter of p-Mg. The GS-loaded Mg-G with larger original pore diameter has higher burst release of GS. Moreover, the in vitro antibacterial test of the GS-loaded Mg-G indicated that this biomaterial has obvious antibacterial effect. This study can provide information for p-Mg loaded with drug(s) as functional bone repair materials with drug-delivery capabilities. [ABSTRACT FROM AUTHOR]

Porous titanium with entangled wire structure was enhanced by filling gelatin into the porous structure to form a titanium-gelatin (Ti-G) composite. The density of the composites was 1.6–2.5 g/cm 3 , similar to that of bone. The strength and elastic modulus of the composites reached 12.9–39.4 MPa and 2.5–7.4 GPa, respectively, which were comparable to that of the cortical bone. Gelatin in Ti-G composite acted as the carrier of gentamicin sulphate (GS). Antibacterial efficacy of GS-loaded Ti-G against Staphylococcus aureus strain was tested. The lack of growth of Staphylococcus aureus strains was found in Luria–Bertani (LB) medium containing GS-loaded Ti-G. GS release behavior from the GS-loaded Ti-G composites in phosphate buffer saline (PBS) was investigated. The effective GS release times from Ti30-G and Ti50-G were 120 h and 168 h, respectively. The gelatin in Ti-G was just degraded 3.2% at the immersion time of 168 h and 9.0% at 336 h. The degradation rate of gelatin was much slower than release rate of GS, indicated that the GS release from gelatin was less affected by the gelatin degradation. These Ti-G composites loaded with drug(s) are expected to be good candidates as functional bone repair materials with drug-delivery capabilities. [ABSTRACT FROM AUTHOR]

The degradation behavior of the porous titanium with entangled structure filled with biodegradable magnesium (p-Ti/Mg) in Hanks' solution was investigated. It was found that the p-Ti/Mg composite had higher strength than pure magnesium and porous titanium with entangled structure (p-Ti). Although the magnesium in p-Ti/Mg was completely dissolved in Hanks' solution after immersion for 104 h, the rest of the sample still maintained strength of about 86 MPa. Moreover, the produced porousness (due to magnesium-degradation) could provide channels for the ingrowth and transportation of bone cells. However, the high corrosion rate of p-Ti/Mg is still a problem when used as a candidate biomedical material, which needs further improvement. [ABSTRACT FROM AUTHOR]

A kind of graded porous titanium–magnesium (Ti–Mg) composite, i.e., about 1–1.5 mm thick porous Ti layer is wrapped over the internal dense Ti–Mg composite, has been successfully fabricated by infiltration casting and acid etching. The outer porous Ti layer maintains its initial entangled structure, which can be easily adjusted to the ideal porosity and the porous structure. The thickness of the porous layer can be controlled by etching time. When the outer porous layer accounted for 41.6–42.4% of the total volume of the cylindrical sample, the compressive strength and the Young’s modulus of the as-prepared graded porous composite are 110 MPa and 5 GPa, respectively, being comparable to that of natural bone. The outer porous layer provides good osteoconduction ability, and the internal dense Ti–Mg composite contributes to the monolithic strength and stiffness. Such biomechanical properties suggest its potentials for load-bearing bio-applications. [ABSTRACT FROM AUTHOR]